Conventionally, there is a switching device that includes multiple input terminals connected with multiple voltage sources, respectively, and an output terminal connected with a power-supplied device and selectively switches connections between the multiple voltage sources and the power-supplied device.
In the switching device, each switching path that connects each of the multiple voltage sources and the power-supplied device includes a first and a second enhancement-type P-channel MOS transistors. The switching device connects the drain electrode of the first enhancement-type P-channel MOS transistor with the source electrode of the second enhancement-type P-channel MOS transistor.
Also, the switching device connects the gate electrode of the first enhancement-type P-channel MOS transistor with the output terminal, and connects the gate electrode of the second enhancement-type P-channel MOS transistor with the input terminal (see, for example, Patent Document 1).